Advising individuals with allergies on their suitability for COVID-19 Vaccine AstraZeneca

Ashley Marsden, Senior Medicines Optimisation Pharmacist, Pharmacy Practice Unit, Royal Liverpool HospitalPublished Last updated See all updates

Advice on whether people with a previous allergic reaction can have the COVID-19 Vaccine AstraZeneca.

Background

Individuals due to be vaccinated may have had previous allergies, and may ask their healthcare professional for advice on their suitability for vaccination.

UK Health Security Agency (UKHSA – formerly known as PHE) Immunisation Against Infectious Disease (the Green Book) states that:

  • those with allergies, including anaphylaxis, to a food, insect sting or most medicines (where the trigger has been identified), can proceed with vaccination as normal according to local guidelines, as long as they are not known to be allergic to any component (excipient) of the vaccine;
  • anyone with a family history of allergies, a previous non-systemic reaction to a vaccine, hypersensitivity to non-steroidal anti-inflammatory drugs (e.g. aspirin, ibuprofen) or mastocytosis can proceed with vaccination as normal, according to local guidelines.

Below is a summary of knowledge about suitability for vaccination based on previous allergy status.

First dose of COVID-19 vaccine allergy

Only a very small number of individuals have experienced anaphylaxis when receiving a COVID-19 vaccine. Allergy to a previous dose of AstraZeneca COVID-19 vaccine or any of its components (excipients) may affect suitability for vaccination.

Previous reaction to AstraZeneca vaccine

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) provides the following information:

  • Individuals with a prior systemic anaphylaxis reaction to AstraZeneca vaccine may be given an alternate vaccine in any setting, with observation for 30 minutes.
  • for individuals without any objective signs of anaphylaxis and for whom symptoms rapidly resolved (with no more than 1 dose of IM adrenaline), a further dose of AstraZenecca vaccine can be given in any vaccination setting (see our decision tool for information relating to required observation times).
  • individuals with non-allergic reactions (vasovagal episodes, non-urticarial skin reaction or non-specific symptoms) can receive further doses of AstraZeneca vaccine in any vaccination setting. Observation for at least minutes post vaccination is recommended.

Our decision tool below will guide you through treating patients with prior allergy.

COVID-19 Vaccine Prior Allergy Decision Tool

Advice end-points

Seek advice from Allergy Specialist

If no respiratory or cardiovascular compromise, and symptoms rapidly resolved with a maximum of ONE dose of IM adrenaline, individuals can receive a further dose of the SAME vaccine in any care setting.

Observe for at least 30 minutes and consider pre-treatment with a dose of non-sedating antihistamine at least 30 minutes before vaccination.

Note that pre-treatment with antihistamines may mask initial symptoms of a reaction.

Give further dose, using the SAME vaccine in any vaccination setting. Observe for at least 30 minutes.

Consider pre-treatment with non-sedating antihistamine, at least 30 minutes before vaccination

Give further dose of the SAME vaccine in any vaccination setting. Observe for at least 15 minutes.

Consider pre-treatment with non-sedating antihistamine at least 30 minutes before vaccination.

On advice of a specialist, consider administration of the implicated mRNA vaccine under medical supervision in hospital. Where reaction was to AstraZeneca vaccine, give alternative vaccine in any setting.

Observe for at least 30 minutes and consider pre-treatment with a dose of non-sedating antihistamine at least 30 minutes before vaccination.

Note that pre-treatment with antihistamines may mask initial symptoms of a reaction.

(Anaphylaxis, i.e. objective respiratory and/or cardiovascular compromise, usually with skin signs)

Excipients

The manufacturer’s information states that hypersensitivity to any of the excipients is a contraindication to the vaccine use.

Excipients present

The excipients listed in the manufacturer’s information are as follows:

  • L-Histidine
  • L-Histidine hydrochloride monohydrate
  • Magnesium chloride hexahydrate
  • Polysorbate 80 (E 433)
  • Ethanol
  • Sucrose
  • Sodium chloride
  • Disodium edetate dihydrate
  • Water for injections

Polysorbate 80 allergy

The AstraZeneca COVID-19 vaccine contains polysorbate 80, according to the manufacturer’s information and use would therefore be contra-indicated in anyone with an allergy to this excipient. Individuals with an allergy to polysorbate 80 should not receive the vaccine, and should be discussed with an allergist.

Polyethylene glycol (PEG) allergy

PEG is not present in the AstraZeneca COVID-19 vaccine, according to the manufacturer’s information; however, it does contain polysorbate 80. UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) advises that some people with PEG allergy may rarely also be allergic to polysorbate 80. However, polysorbate is widely used in medicines and foods, and is present in many medicines including monoclonal antibody preparations. Some injected influenza vaccines (including the main vaccine used in over 65 year olds) contain polysorbate 80. Individuals who have tolerated injections that contain polysorbate 80 (including the adjuvanted influenza vaccine, Fluad® and the GlaxoSmithKline vaccine Fluarix®) are likely to tolerate the AstraZeneca vaccine.

The rate of anaphylaxis reported to date after the AstraZeneca vaccine is in line with the expected rate of anaphylaxis to non-COVID vaccines.

Therefore, unless otherwise contraindicated, the Green Book  advises that the AstraZeneca COVID-19 vaccine may be used as an alternative in people with a PEG allergy, or a suspected PEG allergy, particularly if they previously tolerated an injected influenza vaccine containing polysorbate 80 e.g. Fluad® or Fluarix®. Consider discussing such patients with an allergist prior to vaccination.  If vaccination proceeds, it should be administered in a setting with full resuscitation facilities (e.g. a hospital), and a 30 minute observation period is recommended; some patients may benefit from pre-treatment with antihistamine – however, be aware that this may mask initial symptoms of a reaction. (See also the “Medicines allergy” section below).

Medicines allergy

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) states that individuals with previous allergy to a medicine (where the trigger has been identified), including anaphylaxis, can receive the AstraZeneca COVID-19 vaccine. People with hypersensitivity to nonsteroidal anti-inflammatory drugs e.g. aspirin or ibuprofen, can also receive the AstraZeneca COVID-19 vaccine. However, the Green Book also states that PEG allergy should be considered in the following individuals (see also ‘PEG allergy’ section above):

  • Those with a history of immediate anaphylaxis to multiple, different drug classes with the trigger unidentified.
  • Those with a history of anaphylaxis to a vaccine, an injected antibody preparation or a medicine likely to contain PEG (e.g. depot steroid injection, laxative)
  • a history of idiopathic anaphylaxis

Seek allergy specialist advice regarding PEG allergy and possible crossover with polysorbate 80 if needed (see ‘PEG allergy’ above for further detail.

See also the UK Chemotherapy board Clinician Frequently Asked Questions (FAQs) and guidance on COVID-19 vaccine for patients receiving Systemic Anti-Cancer Therapy (May 2021).  This has been produced in response to questions about use of COVID-19 vaccines in patients who have experienced a reaction to systemic anti-cancer therapy (SACT) or excipients of SACT.

The Children’s Cancer and Leukaemia group have produced advice for children who may be receiving PEG containing drugs.

Antibiotics

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) states that individuals with previous allergy to a medicine (where the trigger has been identified), including anaphylaxis, can receive the AstraZeneca COVID-19 vaccine.

“Sulfa” medicines

UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) states that individuals with previous allergy to a medicine (where the trigger has been identified), including anaphylaxis, can receive the AstraZeneca COVID-19 vaccine.

The manufacturer’s information does not indicate that any “sulfa” medicines are present in the AstraZeneca COVID-19 vaccine.

Other allergy considerations

As well as allergy considerations associated with previous vaccination and to excipients, other considerations are as follows.

Foods

Previous allergy to foods is covered in UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book) which states that individuals with previous allergy to food, including anaphylaxis, can receive the AstraZeneca COVID-19 vaccine.

The manufacturer states that AstraZeneca COVID-19 vaccine does not contain:

  • Egg
  • Gelatin
  • Gluten
  • Peanut or tree nut derivatives
  • Soy

However, AstraZeneca does not manufacture the raw materials used in its products, and the suppliers may periodically change. Lack of contact with other ingredients during the manufacturing process, such as the ones listed above, cannot be guaranteed.

Latex

Our view is that the risks associated with previous latex allergy are low. The vaccine can be considered not to contain latex and poses the same minimal risk as other injectable medicines presented in vials with a halobutyl rubber stopper.

This view is formed from:

However, even if the components of an injection do not contain latex, or latex is not used as a raw material during manufacturing, most manufacturers of injectable products advise they cannot guarantee minute amounts of latex are not contained in raw materials obtained from their suppliers or the product has not come into contact with latex during the manufacturing process.

Patients with an allergy to latex can be directed to the Anaphylaxis Campaign website for information.

Thiomersal content

The manufacturer states that this vaccine does not contain any preservatives, thiomersal or any mercury derived product.

Summary of allergy considerations

The table below is a pictorial summary of the management of patients with a history of allergy, reproduced with kind permission from authors of UK Health Security Agency (UKHSA) Immunisation Against Infectious Disease (the Green Book).

Also of interest

Managing anaphylaxis in the COVID-19 vaccination setting

Advice on managing anaphylaxis in the vaccination setting with specific reference to COVID-19 vaccines.

Change history

  1. Image of summary table updated in line with Green Book amendment
  2. Text amended in previous reaction to vaccine section to state that individuals with prior non-allergic reactions should be observed for at least 15 minutes post-vaccination.
  1. Removed the statement in the PEG allergy section that polysorbate 80 is found in many vaccines and there are no reports of PEG-allergic patients reacting to it e.g. when receiving other vaccines, as the the BSACI COVID-19 Vaccinations and Allergies FAQ no longer states this and updated with advice from the Green Book.
  1. Page, tool and image updated to reflect changes in green book regarding management of those with prior allergy to vaccine and PEG. Links updated.
  1. PEG and polysorbate 80 sections updated and editorial changes made.
  1. Addition of COVID-19 Vaccine Prior Allergy Decision Tool and made other editorial changes.
  1. Changed 'First dose of AstraZeneca COVID-19 vaccine or other medicines allergy' heading to 'First dose of AstraZeneca COVID-19 vaccine allergy'.
  2. Removed 'Individuals with a history of immediate onset-anaphylaxis to multiple classes of drugs or an unexplained anaphylaxis should not be vaccinated with the Pfizer-BioNTech COVID-19 vaccine, except on the advice of an allergy specialist. However, the AstraZeneca COVID-19 vaccine can be used as an alternative (if not otherwise contraindicated), particularly if they previously tolerated an injected influenza vaccine. The vaccine should be administered in a setting with full resuscitation facilities (e.g. a hospital), and a 30 minute observation period is recommended' from 'First dose of AstraZeneca COVID-19 vaccine allergy' section as it is also in the PEG section.
  1. Removed 'Patients with systemic allergic symptoms after the first dose of the Pfizer-BioNTech vaccine may be considered for a second dose using the AstraZeneca vaccine, and should be observed for 30 minutes following vaccination' from PEG section as this was from an older version of the Green Book.
  1. Removed the statement in the PEG 80 allergy section that although polysorbate 80 is quite similar in structure to PEG, there are no reports of PEG-allergic patients reacting to it (e.g. when receiving other vaccines), as the BSACI COVID-19 Vaccinations and Allergies FAQ no longer states this; updated the section with information from the Green Book on polysorbate 80 and flu vaccines.
  2. Link added to the UK Chemotherapy board Clinician Frequently Asked Questions (FAQs) and guidance on COVID-19 vaccine for patients receiving Systemic Anti-Cancer Therapy in 'other drugs' section.
  1. Information on prior allergy common to all vaccines moved the main page covering common allergy points.
  1. Added "Flowchart for managing patients who have allergic reactions to the first dose of COVID-19 vaccine" to "First dose of AstraZeneca COVID-19 vaccine or other medicines allergy" section; added a new section "Summary of allergy considerations", including a summary table.
  1. Updated to reflect changes in the Green Book: "Background" section updated; "First dose of AstraZeneca COVID-19 vaccine or other medicines allergy" section updated, including addition of BSACI management advice for people who had a reaction to the first dose of vaccine; added which patients should be discussed with an allergy specialist prior to vaccination in the "other drugs" section.
  1. Changes made to clarify advice in relation to allergies and excipients
  2. Changes made to include page as part of a series covering similar topics
  3. Changes made to clarify advice in relation to other allergy considerations, including addition of advice regarding latex
  1. Polysorbate 80 information added.
  1. PEG section modified, based on updated information from the Green Book.
  1. Published